If you like games play this.... NOW!
In this game you can basically pick your own path to a destiny that has been decided for you long ago by the nine gods who created this world long long ago. However you dont have to follow that path to the letter nor do you really have to do it at all but it would be very hard to aviode doing the main quest.
This would seems very complex at first but after about 2-3h you more or less get the hang of whats happining and y its like that. Also the story makes it very easy to get into heres an example... The first time i went into an Obivion Gate I was assulted by a small army of very evil things, a knight who had come into the gate before my lie dead on the groud blood around him. I could here the cries of another knight as he was being killed by the army that was headed for me, I raised my sword and charged towards the group that killed my fellow Knights, my sword cut down two of the demons. I fired a spell at the 3ed Demon, and he died slowly falling to the ground. I knew then i would not leave this place until i had killed every demon, freed every prisoner, and Destroyed this Gate.
Thats just one small part in one small chapter in th very large book of Oblivion